1. Field of the Invention
The invention relates to a device for processing a finish on the surface of work pieces. The device has a feed unit with a slide and a drive that is Numerically Controlled (NC)-controlled, a motorized spindle unit with a motor-driven tool spindle. There is also a device for measuring the force of contact pressure that is brought to bear upon the tool spindle in conjunction with a processing of a work piece.
2. The Prior Art
The prior art in German Patent No. DE 39 30 457 A1 shows a process of measuring the force of the contact pressure that is brought to bear upon the tool spindle continually in the course of processing a work piece. The process subsequently regulates, by degrees, the contact pressure of the processing tool on the surface of the work piece, to a pre-determined limit at which there is an optimal removal of material. Furthermore, German Patent No. 197 38 818 A1 describes a process wherein, depending upon deviations in the measurements, and the form of the geometry of the work piece, the device controls the contact pressure or rather, the feed, of the work piece to be processed. The tool support is equipped with a measuring device that has a precision indicator and supporting elements.
In processing the finish of work pieces that have small parts, such as seating surfaces of fuel injector valves, or flat surfaces of miniature pressure sensors, etc., precision-guided feeding motions of the rotating grinding tool are necessary to meet the high standards for retaining the dimensions and the surface quality of the processed work piece. The feed must be set so that the processing tool lies against the surface of the prospectively processed work piece with a defined force that can be adjusted in a very sensitive manner. As a rule, contact forces of less than 100 N must be set and, in the case of very small work pieces, contact forces on an order of magnitude of 1 to 25 N must be set.